Formation of integrated circuit structures of a semiconductor device may utilize plating processes. During plating, a metal or other electrically conductive material is plated from an exposed surface. In certain implementations the electrically conductive material takes the form of contacts, solder bumps, etc. that are utilized to interconnect the semiconductor device to external circuitry.
The Restriction of Hazardous Substances Directive (RoHS) restricts the use of certain hazardous substances in electrical and electronic equipment and has driven the electronics industry to move away from solders that contain Lead (Pb). As a result, lead-free solder material, such as Tin (Sn), may now be utilized in the solder bump plating processes.
In order to reduce soft errors within the semiconductor device it may be beneficial to utilize low alpha particle emitting electrically conductive materials in the plated electrically conductive materials. A low alpha particle emitting electrically conductive material is an electrically conductive material having an alpha particle emissivity value of less than 2α/cm2/1000 hours. However, the cost of low alpha particle emitting electrically conductive materials may be 2-7 times the cost of the associated raw material which may include a trace amount of alpha particle emitting particles.